code: def isnan(x):
      return x != x
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import torch
  import torch.nn.functional
  from torch import nn
  from torch.autograd import Variable
label_desc: Use image node_id 12 for calling a global function with example usage: isnan(x) and returns: unknown